Disclosed is a method for continuously authenticating a user based on motion input data. The method includes recording motion input data from a keyboard such as starting coordinates, ending coordinates, and timestamps of key-up actions to determine that a key has been pressed, recording a timestamp of motion input at the starting coordinate, mapping the timestamp of said motion input at the starting coordinate to a key-down action for the key press, determining which key of said virtual keyboard said key-down action refers to, and granting or denying access to a device if the timing of the key which was pressed and released in the key-down action and the corresponding key-up action matches the press and flight timing of a key which was pressed and released in a previously-recorded key-down action and a previously-recorded key-up action.